graphviz

Documentation

Overview

Package graphviz provides a concrete prettyprinters.DigraphPrettyPrinter implementation for rendering directed graphs as Graphviz-compatible dot source files. It exports an interface, graphviz.PrintProvider, that allows users to provide general methods for rendering graphed data types into graphviz documents.

Index

• type BasicProvider
  • func (p BasicProvider) EdgeGetLabel(GraphEntity, GraphEntity) (pp.VisibleRenderable, error)
  • func (p BasicProvider) EdgeGetProperties(GraphEntity, GraphEntity) PropertySet
  • func (p BasicProvider) SubgraphMarker(GraphEntity) SubgraphMarkerKey
  • func (p BasicProvider) VertexGetID(e GraphEntity) (pp.VisibleRenderable, error)
  • func (p BasicProvider) VertexGetLabel(e GraphEntity) (pp.VisibleRenderable, error)
  • func (p BasicProvider) VertexGetProperties(GraphEntity) PropertySet
• type GraphEntity
• type GraphIDProvider
  • func (p GraphIDProvider) VertexGetID(e GraphEntity) (pp.VisibleRenderable, error)
  • func (p GraphIDProvider) VertexGetLabel(e GraphEntity) (pp.VisibleRenderable, error)
• type Options
  • func DefaultOptions() Options
• type PrintProvider
  • func DefaultProvider() PrintProvider
  • func IDProvider() PrintProvider
• type Printer
  • func New(opts Options, provider PrintProvider) *Printer
  • func (p *Printer) DrawEdge(g *graph.Graph, id1, id2 string) (pp.Renderable, error)
  • func (p *Printer) DrawNode(g *graph.Graph, id string) (pp.Renderable, error)
  • func (*Printer) FinishPP(*graph.Graph) (pp.Renderable, error)
  • func (*Printer) FinishSubgraph(*graph.Graph, pp.SubgraphID) (pp.Renderable, error)
  • func (p *Printer) GraphAttributes() string
  • func (p *Printer) MarkNode(g *graph.Graph, id string) *pp.SubgraphMarker
  • func (p *Printer) StartPP(*graph.Graph) (pp.Renderable, error)
  • func (p *Printer) StartSubgraph(g *graph.Graph, startNode string, subgraphID pp.SubgraphID) (pp.Renderable, error)
• type PropertySet
• type SubgraphMarkerKey

Types

type BasicProvider

type BasicProvider struct{}

A BasicProvider is a basic PrintProvider for Graphviz that uses the value in the default format (%v) as the node label and id.

func (BasicProvider) EdgeGetLabel

func (p BasicProvider) EdgeGetLabel(GraphEntity, GraphEntity) (pp.VisibleRenderable, error)

EdgeGetLabel provides a basic implementation leaves the edge unlabeled.

func (BasicProvider) EdgeGetProperties

func (p BasicProvider) EdgeGetProperties(GraphEntity, GraphEntity) PropertySet

EdgeGetProperties provides a basic implementation that returns an empty property set.

func (BasicProvider) SubgraphMarker

func (p BasicProvider) SubgraphMarker(GraphEntity) SubgraphMarkerKey

SubgraphMarker provides a basic implementation that returns a NOP.

func (BasicProvider) VertexGetID

func (p BasicProvider) VertexGetID(e GraphEntity) (pp.VisibleRenderable, error)

VertexGetID provides a basic implementation that returns the %v quoted value of the node.

func (BasicProvider) VertexGetLabel

func (p BasicProvider) VertexGetLabel(e GraphEntity) (pp.VisibleRenderable, error)

VertexGetLabel provides a basic implementation that returns the %v quoted value of the node (as with VertexGetID).

func (BasicProvider) VertexGetProperties

func (p BasicProvider) VertexGetProperties(GraphEntity) PropertySet

VertexGetProperties provides a basic implementation that returns an empty property set.

type GraphEntity

type GraphEntity struct {
	Name  string      // The canonical node ID
	Value interface{} // The value at the node
}

GraphEntity defines the value at a given vertex, providing both it's canonical name and the untyped value associated with the vertex.

type GraphIDProvider

type GraphIDProvider struct {
	BasicProvider
}

A GraphIDProvider is a basic PrintProvider for Graphviz that uses the Node ID from the digraph as the Vertex ID and label.

func (GraphIDProvider) VertexGetID

func (p GraphIDProvider) VertexGetID(e GraphEntity) (pp.VisibleRenderable, error)

VertexGetID provides a basic implementation that uses the ID from the graph to generate the VertexID.

func (GraphIDProvider) VertexGetLabel

func (p GraphIDProvider) VertexGetLabel(e GraphEntity) (pp.VisibleRenderable, error)

VertexGetLabel provides a basic implementation that uses the ID from the graph to generate the Vertex Label.

type Options

type Options struct {
	// Specifies the way that connections between verices are drawn.  The default
	// is 'spline', other options include: 'line', 'orth', and 'none'.  See
	// http://www.graphviz.org/doc/info/attrs.html#d:splines
	Splines string

	// Specifies the direction of the graph.  See
	// http://www.graphviz.org/doc/info/attrs.html#d:rankdir for more information.
	Rankdir string
}

Options specifies global graph options that can be configured for output. Arbitrary graphviz options are not supported.

func DefaultOptions

func DefaultOptions() Options

DefaultOptions returns an Options struct with default values set.

type PrintProvider

type PrintProvider interface {

	// Given a graph entity, this function shall return a unique ID that will be
	// used for the vertex.  Note that this is not used for display, see
	// VertexGetLabel() for information on vertex displays.
	VertexGetID(GraphEntity) (pp.VisibleRenderable, error)

	// Defines the label associated with the vertex.  This will be the name
	// applied to the vertex when it is drawn.  Labels are stored in the vertex
	// attribute list automatically.  The 'label' parameter should therefore not
	// be returned as part of VertexGetProperties().
	VertexGetLabel(GraphEntity) (pp.VisibleRenderable, error)

	// VertexGetProperties allows the PrintProvider to provide additional
	// attributes to a given vertex.  Note that the 'label' attribute is special
	// and should not be returned as part of this call.
	VertexGetProperties(GraphEntity) PropertySet

	// Defines the label associated with the edge formed between two graph
	// entities.  This will be the name applied to the edge when it is drawn.
	EdgeGetLabel(GraphEntity, GraphEntity) (pp.VisibleRenderable, error)

	// EdgeGetProperties allows the PrintProvider to provide additional
	// attributes to a given edge.  Note that the 'label' attribute is special
	// and should not be returned as part of this call.
	EdgeGetProperties(GraphEntity, GraphEntity) PropertySet

	// Allows the underlying provider to identify vertices that are the beginning
	// of a subgraph.  The function should return one of:
	//   SubgraphMarkerStart
	//   SubgraphMarkerEnd
	//   SubgraphMarkerNOP
	// in order to specify the vertexs' relation to subgraphs.
	SubgraphMarker(GraphEntity) SubgraphMarkerKey
}

PrintProvider allows specific serializable types to be rendered as a Graphviz document.

func DefaultProvider

func DefaultProvider() PrintProvider

DefaultProvider returns an empty BasicProvider as a convenience

func IDProvider

func IDProvider() PrintProvider

IDProvider is a convenience function to generate a GraphIDProvider.

type Printer

type Printer struct {
	// contains filtered or unexported fields
}

Printer is a DigraphPrettyPrinter implementation for drawing graphviz compatible DOT source code from a digraph.

func New

func New(opts Options, provider PrintProvider) *Printer

New will create a new graphviz.Printer with the options and print provider specified.

func (*Printer) DrawEdge

func (p *Printer) DrawEdge(g *graph.Graph, id1, id2 string) (pp.Renderable, error)

DrawEdge prints edge data in a fashion similar to DrawNode. It will return a visible Renderable IFF the source and destination vertices are visible.

func (*Printer) DrawNode

func (p *Printer) DrawNode(g *graph.Graph, id string) (pp.Renderable, error)

DrawNode prints node data by calling VertexGetID(), VertexGetLabel() and VertexGetProperties() on the associated print provider. It will return a visible Renderable IFF the underlying VertexID is renderable.

func (*Printer) FinishPP

func (*Printer) FinishPP(*graph.Graph) (pp.Renderable, error)

FinishPP returns the closing '}' to end the DOT file.

func (*Printer) FinishSubgraph

func (*Printer) FinishSubgraph(*graph.Graph, pp.SubgraphID) (pp.Renderable, error)

FinishSubgraph provides the closing '}' for a subgraph

func (*Printer) GraphAttributes

func (p *Printer) GraphAttributes() string

GraphAttributes returns a string containing all of the global graph attributes specified in Options.

func (*Printer) MarkNode

func (p *Printer) MarkNode(g *graph.Graph, id string) *pp.SubgraphMarker

MarkNode will call SubgraphMarker() on the print provider to determine whether the current node is the beginning of a subgraph.

func (*Printer) StartPP

func (p *Printer) StartPP(*graph.Graph) (pp.Renderable, error)

StartPP begins the DOT output as an unnamed digraph.

func (*Printer) StartSubgraph

func (p *Printer) StartSubgraph(g *graph.Graph, startNode string, subgraphID pp.SubgraphID) (pp.Renderable, error)

StartSubgraph returns a string with the beginning of the subgraph cluster

type PropertySet

type PropertySet map[string]string

PropertySet is a map of graphviz compatible node or edge options and their values. See http://www.graphviz.org/doc/info/attrs.html for a list of supported attributes. Node that graph and subgraph attributes are not currently supported.

type SubgraphMarkerKey

type SubgraphMarkerKey int

SubgraphMarkerKey is a type alias for an integer and represents the state values for subgraph tracking.

const (
	// SubgraphMarkerStart specifies that the current node is the beginning of a
	// subgraph.
	SubgraphMarkerStart SubgraphMarkerKey = iota

	// SubgraphMarkerEnd pecifies that the current node is the end of a subgraph.
	SubgraphMarkerEnd

	// SubgraphMarkerNOP pecifies that the current node should not change the
	// subgraph state.
	SubgraphMarkerNOP
)